DE1618067A1 - Process for the production of adipic acid nitrile by electrolytic hydrodimerization of acrylonitrile - Google Patents

Description

16180a?

PATENT LAWYERS

DR.-IN6. VON KREISLE * DR.-1NG. SCHO'N'W'ALD DR. = IMG.TH. MiYER DR..FUES DiPL-CHEM. ALEK FROM KREISLER

DR.-IN6-. KLQPSCH

COLOGNE 1 / DEICHMANNHAUS

ρ 16 Ib 067.9

Asahi K asei Eogyo Kab ushiki galsha » .

25-1 % 1 «° -ohome ₈ Bojima-Hamadori, Kita ~ ku» Osaka (Japan)

¥ experienced for the production of mipinonitrile electrolytic hydrodimerization of acrylonitrile

The invention “relates to the production of adiponitrile by electrolytic hydrodimerization of acrylonitrile ₀

It is "known: that by electrolysis of an acrylonitrile solution, which contains a conductive salt, the acrylonitrile can be converted into adiponitrile at the cathode. When trying this electrolytic "dimerization However, difficulties have arisen to carry out in practice. In general, the yield is of adiponitrile is relatively low, and the efficiency of the electrolysis is low. the natural solubility of acrylonitrile in an aqueous Solution is relatively low, and when electrolyzing a solution, this is proportionate contains small amounts of aeryl nitrile, it has been shown that that very little adiponitrile and predominantly propionitrile is formed «,

It has already been suggested to go through this Haehteil Switch off the use of a conductive salt, which the

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New documents (Art.? 3 ί AU 2? 4r. I sentence 3 of the amendment a. V. 4. t. VtSM

Dissolution of substantially larger amounts of aopylnitrile in the electrolyzing solution is made possible (see US Pat. Nos. 3,193,481, 3,193,480 and 3,193,477). In di @ s®n USA PateatSchriften a minimum amount of kindly dissolved acrylonitrile of 5 Gewo-ji is suggested »in order to achieve an advantageous effect with regard to the suppression of propionitrile formation, but in fact much higher amounts of acrylonitrile well above 10 $ must be kept in solution.» At low

Ί0 ran concentrations approaching a height of 10 $ is the process uneconomical formed by increased PropionitrilMldung, and when the concentration of a height of 5 # passes, is practically no Adipinsäurenitril "The L _e itsalze that the acrylonitrile in the for Solubilizing the aqueous solution used in electrolysis are relatively expensive. Furthermore, increases with increasing concentration of dissolved acrylonitrile and the tendency to form trimers and high molecular PoIymerisationsprodukten to _e It was proposed to add inhibitors of free-radical polymerization of the solution to be electrolyzed to prevent this, but this measure proved to be ineffective ,,

In the French patent 1 401 175 was suggested electrolysis using sodium hydroxide as a conductive salt and an auxiliary, which contains hydrophilic and hydrophobic groups, to carry out in order to increase the solubility of the acrylonitrile increase and maintain an excess of acrylonitrile so that s3.ne dissolution up to the maximum possible Extent is ensured · When using sodium hydroxide or a gate step of sodium hydro xyd as a conductive salt, however, increases the p ^ value of the

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Solution Me su a relatively high WTRB of usually about 12 to about · U _n Under these conditions makes calibrating an undesirable formation of BtLsoyanäthyläther noticeable if the temperature nioht below 5 ⁰ C is maintained "Further, the presence of excess undissolved acrylonitrile in Elektrolyeierraum a polymerisation which not only solves the yield, but also prevents the continuous operation of the electrolysis cell

None of the suggestions made so far proved successful as completely satisfactory or feasible for large-scale electrolytic hydrodimerization from acrylonitrile to adipic acid nitrile.

The invention relates to a novel process for elektrolytisohen Hydrödimerisierung of acrylonitrile, the OUBLE the difficulties and F _r of the known method turns off. This new process enables the use of relatively small amounts of dissolved acrylonitrile below 5% by weight, while at the same time the formation of pyopionitrile is suppressed and the formation of adiponitrile is made possible in yields and with an efficiency which were previously unattainable the problem of the formation of trimers and closer polymers in the electrolytic production of adiponitrile and acrylonitrile, which is present in the known processes, is eliminated

Definitions!

The meaning of certain expressions used in this description and in the claims, is given below. -

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"Conductive salt" is a salt that is an emulsion or solution, which contains the acrylonitrile, maoht conductive and the Hydrodimerization of the aorylnitrile to adipinonitrile enables and works under these conditions does not separate from the cathode,

"Oligomer" is a low molecular weight material which mainly consists of a hydrotrimer or hydrotetramer τοη acrylonitrile, e · B ₀ 2-cyanoethyladiponitrile and the like · "

“Polymer ¹¹ is a low molecular weight β polymer τοη aoryl nitrile with a molecular weight of more than about 300, determined from the intrinsic viscosity.

"Anionic polymerization inhibitor ¹¹ is an additive that is produced by an electric current or inhibits or suppresses an electric field or potential-triggered polymerization, in contrast to the polymerization triggered by free radicals, de ho is an inhibitor that see Meohanismus proceeding polymerization suppressed · IfcLeser inhibitor of the anioni sohen polymerization is of an inhibitor of the free radicals To differentiate polymerization, its effectiveness is only due to the prevention of the 'formation of free Radicals

According to the invention, adipic acid trile is produced, by an electrolyzing current through an emulsion is directed, the one oil phase, one closed aqueous phase, a Leitsale, aoryl nitrile and preferably an inhibitor of anionic polymerization Contains · The aoryl nitrile must be in the aqueous phase

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be distributed in a dissolved form and in a concentration ■ tration of less than 5 wt ~ 6 and in the oil phase in

'Are present in such an amount that acrylonitrile in the aqueous phase is replenished when this phase

.5 depleted Aorylnitril me electrolysis with any known or conventional El EKTR ^ performed ₀ It is important that the! Liquid present in the region of the cathode where the desired electrolysis takes place in the form of a true emulsion. And the emulsified oil phase must be in the area of the cathode surface. According to the invention, a true electrolysis of an emulsion thus takes place in the. In contrast to electrolysis using a solution that contains excess aorylnitrile or emulsified aorylnitrile particles away from the area of the ethodal surface in order to facilitate dissolution and to keep the solution saturated with acrylonitrile

When it is mentioned here and in the claims, that an electrolyzing current through an emulsion . is passed, so this is specifically limited to the present Pall ", in which the emulsion itself in contact with the cathode is where the "electrolytic Conversion takes place,

Since a sufficient amount of acrylonitrile must be distributed in the oil phase in order to enable a transition of additional aorylnitrile into the solution in the aqueous phase after this phase has been depleted of dissolved aorylnitrile, the amount of aorylnitrile dissolved in the aqueous phase and that present in the oil phase strives Aoryl nitrile equilibrium conditions. In many cases, the aqueous Pj ₁ has ase under these equilibrium conditions, in particular

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if the aoryl nitrile makes up the bulk of the oil phase, the sprinkling, keeping yourself saturated with aoryl nitrile. The anionic polymerization inhibitor should preferably be present in amounts sufficient to suppress polymerization τοη aorylnitrile triggered by an electric current. The presence of aoryl nitrile both in the aqueous phase and in the oil phase _{0 is particularly preferred}

As "already mentioned, electrolysis can take place in" any known or customary electrolysis cells are carried out. The is particularly preferred Carrying out the electrolysis in an electrolysis cell with a diaphragm that connects the cathode " Space separates from the anode space, and with devices for separate circulation of the anolyte and catholyte is provided »As conductive salt can be used in the cell or in the catholyte when using one with a diaphragm Any salts that make the catholyte conductive can be used in the provided cell the cathode does not deposit and the hydrodimerization allow the acrylonitrile by electrolysis.

As conducting salts, organic or inorganic salts 2, for example, salts of alkali or alkaline earth metals are, of lithium, sodium, KaIiUm ₉ rubidium, cesium, beryllium, magnesium, calcium, strontium and barium. Ammonium salts and quaternary ammonium salts of organic and inorganic acids can also be used. B ₀ sulfates, halides, sulfonates, alkyl sulfonates, or salts of organic acids, ζ. Β. Acetates, and their derivatives. Aliphatic quaternary ammonium salts, aromatic, are particularly preferred

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quaternaryβ ammonium salts, heterooyolico quaternary

J ^ wimrt η j ^ τπρ 9 T vm _f n ffmi i oh Tyfcfflfl i lr yi f jäimnTii '^ mp al "ν.Λ , Tetra—

alkanolammonium salts, alkyltrialkanolammonium salts, Dialkyldialkanolammonium salts, alkanoltrialkylammo sodium salts, H-heterooyolic N-alkylammonium salts.

All anions of the lead seal are anions of organic and enorganisic acids in imprint. Preferred sulphate, chloride, broaid, iodide, perohlorate, Phoephat- and Ohiorfafonat anionen, anions of SuI- foneäure, namely arylsulfonic acid and alkaryleulfoii- e acid _t β B anions of benzenesulfonic acid, benzo 1-dieulfonic acid, o-, a- or p-toluenesulfonic acid, o-, m- or p-ethylbeneboleulfonic acid, o-, m- or p-ou-boleulfonic acid, o-, b- or p-tertiary amyrbenzene

Ί5 eulfonic acid, o-, b- or p-HeiyHaensoleulfonic acid,

o- or p-Iylol-4-sulfonic acid, "-ylol-4- or -5- ■ ulfonic & urej Meeitylen-2-aulfonic acid, Durol-3-eulfonic acid, PentaethyllienEoleulionsäurej o-Dipropylbenzol-4-iulfon" acid _for α- or ß -Haphthalineulfoneäuse, o-, »- ο the p-Btphenyleulfonslur e and α -Methyl-ß-naph thaline oil acid, methane sulfonic acid, ithane sulfonic acid, lauryl sulfonic acid and anions of alkyl sulfonic acid ·, «. B. Methyleohwefeleäure, Athyleohwefeleure ■ acid, laurylsohulfuric acid, and the anions of car- bone acids, ε B. formic acid, acetic acid, propionic acid • Acid ₉ oleic acid, oleic acid, triohloreic acid, hexahydrobeneic acid, hiootinic acid, oxalic acid, malonic acid, adipic acid, pumaric acid, malic acid, tartaric acid, phthalic acid and phenylacetic acid etc. clay these anions can solohe, which easily let reduce at the cathode, Haohteile for the Cause hydrodimerization of acrylonitrile. In general, the Lei ta al ζ can consist of any cations and anicnene of the type mentioned above are particularly preferred are quaternary β anaaoni-

umsulfatverljindungen, s · B ₀ tetramethylaomonium sulfate, Ietraathylainmoniumeulfat, Tetrapropylammonium-Bulfat,! niumeulfat, arrimethylTsenzylajmoniumeulfat, triethyl- TDenBOlammoniumBUlfat _f PJienyltrimethylammonluineulfat , Phenyltriethylammonixuaeulfat , Phenyltriethylammoniumäthylsulfat, Tetramethyltoluylenendiammoniumeulfat, and quaternary β ammoniumuneulfonat ·, b · B. Tetraethylammo niximtoluolsilfonat, Tetraäthylanmoniumbenzolsulfonat, Tetraäthylauimoniiuioumoleulfonat, Totraäthylammoniump-äthyllaenzenesulfonat, TetramethylammoniumTdenenzenulfonat, Tetramethylainmonlumtoluoleulfonat, N, N'-Dimethyl piperidinium-o-toluenesulfonat, N, N'-Uimethyl- piperidlumtoluene sulfonate, Ν, Ν'-dimethylpiperidini to "bieph * nyleulfonat _t TetralDutylaamoiiiiunnaphthalineulfonatf Tetrabutylammoniumtoluoleulfonat, TetrapropylammoniumamyllDenzolBulfonat , Tetrapropylammoni ·» um- a-äthyl-ß-naphthalinBulfonat, Tetraäthanola nium-p-toluene sulfonate, Tetraethanolimaoniumoumolsul- fonate, TetratutanolaiBMonlumTjenzolBUlfonat, TetratoitanolasmoniumxyleneBulfonate, Tetrapentylammonium-ptoluenesulfonate , Tetrapentylammoniumhexyljenzenesulfonat, Tetrapentanolanmonium-p-ouinol-3-eulfonat,

Tetrapentanolanmonium'benBolBulfonat, Methyltriethyl-

ammonium toluene sulphonate, methyltriethylanmonium aesitylene-2-eulphonate, trimethylethylammonium sulphonate, trimethylethylammoniumtοluo leulphonate , Tx iäthylpentylammonium-ο - or -fl-naphthalenesulphonate, trimethyl- pentylaramoniumtutyltenzolBUlfonat, trimethylethanol anmonlum'benzenesulfonate ₍ trimethylethanolameoniumtolu- • leulfonat, ITtF

nat, Bf-MethylpyrrodiniumhexylljeneolBulfonat, Η, ΙΓ ¹ -Diethylpiperidiniumtoluoleulfonat, N-Methylpyrrodiniumtoluoleulfonat, Η, ΙΓ'-DiiBopropylmorplioliniumto-

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on the Q -

luenesulfonate, lijN'-DilJUtylmorpholiniumsulfonat, H, IP-

. Misopropylbiphenylmorpholinium sulfonate,] J, B'-dibutylmorpholiniuffi-p-biphenylsulfonate, Phenyltriethylammoniumtoluenesulfonat, Irimethylphenylaiimoniimbenzolsulfo ^

nat, Irimethyinaphthylammoniumtoluolsulfonat, Iftmethylbenzylphenylammoniumtoluolsulfonat, Dibenzyläthylphenylammoniumtoluolsulfonat _ο β · the like, and alkyl sulfates, halides, phosphates and Alkalisulfonate, z · B · Tetramethylammoniümmethylsulfat, iDetraäthylaimaoniuiiiätliylsulfat, Trimethyläthylanmioniumäthylsulfat, Trimethylathylmethylphenylaniinoniumsulfat, Phenyltrimethylainmoniuinjaalogenid, Tetraäthylamnioniümiialogenid, TetrapropylaiiMoniuinhalogenid, Tetratutylainmoniumhalogenid, Kaliumtolüolsulfonat, Katriumbenzolsulfonat and Benzyltrimethylaimnoniumpho sphat .

Primary, secondary and tertiary amine compounds are mentioned as supporting electrolyte salts in "various publications, but they are not suitable for the purposes of the invention, since" when they are used, propionitrile is predominantly formed. These primary, secondary and tertiary amine salts are therefore out of the question as conducting salts for the purposes of the invention _o

Which conductive salt is chosen in each case depends on the desired working conditions and the _{desired concentration of dissolved acrylonitrile below 5 wt. #} - #, which must be maintained in the aqueous phase of the emulsion. Because of the low concentrations of the dissolved acrylonitrile used in accordance with the invention, it is generally undesirable to use a conductive salt that is hydrophobic,

d. contains h · oleophilic groups, e.g. B _e quaternary alkyl, aryl or alkylarylamroonium sulfonic acid salts, or additionally a solubilizer for the aoryi

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- ίο -

nitrile, ζ _β B, an alkyl, aryl or alkaryl sulfonate or sulfate, to be used ..

According to the invention a low, lower than about 5 $> concentration of dissolved Aorylnitril in the aqueous phase is preferably conductive salts are used with sohwachen oleophilic properties Aufreohterhaltung, do h. To dissolve salts "limited ability to Aorylnitril in the aqueous phase, z, B ₀ quaternary ammonium sulfates or halides, which have an added advantage in terms of economy ,,

The amounts of leitseizes which are dissolved in the aqueous phase, can within wide limits variieren.und for example, 1-60 wt _e depending on the desired working conditions - amount S, but will generally be amounts between about 10 and 40 wt, - # preferably »The electrolyte salt should be chosen according to amount and type so that the Pg value of the catholyte can be kept between about 1 and 10, preferably between 3 and 6. The electrolyte salt can be divided between the aqueous phase and the oil phase of the emulsion according to equilibrium considerations, but its presence is actually only required in the aqueous phase.

The emulsion containing the aoryl nitrile can be emulsified in any known or customary manner of aoryl nitrile or a mixture of aoryl nitrile with another organic material manufactured in the manner described below Emulsification can be achieved by mixing, stirring or shaking the ingredients or by using any known mechanical emulsifying

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- ■ 11 *

Devices or mixers are made. Obligatory emulsifiers, 2 «B ₀ surface-active agents and / or Sohutacloids, can be added. Preferred examples are Sohut elco Holde Protein materials, called carboxymethyl cellulose, methyloelluloea, A * thyloellulo ee and tragacanth Examples of preferred surface-active agents are the known soaps or synthetic raw materials, e.g. B. Alkylbenzenesulfonates. The protective colloidal and surfactants are used in the amounts customary for the intended purpose are used.These amounts are between 10 ppm and 10 & ew «-j (· The amount of the oil phase, based on the aqueous phase, can lie within wide limits, and "Was between 5 times the weight and 1/100 of the weight, as a precaution" between the 3 times the weight and t / 10 the weight of the aqueous phase. . ^:: ,,.

The amount of the lustful acrylonitrile in the aqueous phase can vary between 0.1 and 5% by weight lie. The natural Wasserlösliotiktit of acrylonitrile within the eligible konmenden range of operating temperatures is not over 10 i "put out and- is generally from about 7 ^. If higher lomentrations are to be maintained in the aqueous phase, a conductive salt or, in a known manner, an auxiliary agent must be used which has surface-active properties, i.e. contains hydrophilic and hydrophobic groups, however, a relatively low concentration of dissolved acrylonitrile is preferably maintained when following the teaching of the invention, since a high conversion of acrylonitrile to adipine is possible for the first time.

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eäurenitril to achieve without the formation of propionitrile and the use of lower concentration of dissolved acrylonitrile deft advantage of a unbeaohtliohen Qligomerenbildung and economical working conditions ". (Jemaß the invention is preferably a concentration of dissolved acrylonitrile of less than 5 i". Full be bonder preferably a concentration between 2 and 5 wt.

In order to maintain this low concentration of dissolved aoryl nitrile in the aqueous phase, it may be necessary to dissolve an organic diluent in the aqueous phase. Any non-reactive aliphatic or aromatic compounds which are partially, preferably only slightly, soluble in the aqueous phase of the emulsion are suitable as diluents for this purpose. It proved to be most advantageous materials of the type formed in the electrolysis, z * B ₀ Adipinsäurenitril and / or propionitrile ale diluent in an amount sufficient to use, in order to adjust the concentration of dissolved Aorylnitrils in the aqueous phase. In this way, it is possible to reduce the concentration of the aorylnitrile dissolved in the aqueous phase, since the total concentration of the mixture of acrylonitrile and organic diluent in the aqueous phase is approximately the same as the solubility of acrylonitrile in the aqueous phase and a part of the dissolved acrylonitrile "is replaced by the organic diluent when the latter is added"

Also suitable as diluents are, for example, polar or non-polar solvents, e.g. Bo

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Acetonitrile, dioxane, dimethylformamide, dimethyl acetamide, benzene, substituted benzenes * pentane, heptane, hexane, petroleum ether, etc. In certain cases it is advisable to use the electrolysis product as a diluent after processing or reducing it _; . turn around·,

The content of organic diluent can vary between 1 and 50% by weight. Of course, "the diluent of the emulsion is distributed an express itself in the oil phase · The or diluent may represent any desired inteil the oil phase and about 1 - 99 weight _e." - $ make this phase, the concentration of acrylonitrile sin the oil phase "needs only to be so ho oh that the JLerylnitr.il, is available for the transition into the solution in the aqueous phase when the Aorylnitrilkonzentration in this aqueous phase sinks ₀ to this end, the concentration of acrylonitrile in the oil phase should be about 1 36 The conductive salt can also be distributed in the oil phase depending on its solubility. The amount of conductive salt in this phase can, for example, be between about 0 and 50% by weight

Any known inhibitors of polymerizations which proceed according to an anionic mechanism can be used as inhibitors of anionic polymerization. Thus, any compounds which generally effectively prevent anionic polymerization can be used for the purposes of the invention to prevent polymerization during electrolysis. » In general, the inhibitors of anionic polymerization are compounds _s

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-H-

which reduce the negativity of a double bond and also prevent acrylonitrile from covering the surface of the cathode by stabilizing the emulsion in the vicinity of the cathode and thus ensuring that the cathode is contacted by the emulsion Inhibitors of anionic polymerization both in the oil phase and also in the aqueous phase of the emulsion. Accordingly, preference is given to inhibitors of anionic polymerization "which contain polar and non-polar, ie oleophilic and hydrophilic groups. Particularly advantageous compounds having active hydrogen, z "B ₉ amines, ammonia, salts of amines and ammonia" alcohols "organic and inorganic acetates, Aoetylenverbindungen u. Like _o Water is a compound containing active hydrogen, but is not suitable alone as inhibitor of the anionic polymerization in the invention · However, it has been found that water in combination with a Sohutzkolloid, z _e B ₀ one of the above Sohutzkolloide, is effective as an inhibitor of the anionic polymerization, and this combination is one of the inventively used inhibitors the anionic polymerization ,, oxygen and oxygen-containing compounds, e.g. »carbon oxide, carbon dioxide and carbon oxysulphide, as well as sulfur compounds, ζ ρ B. mercaptans, carbon subsulphide ^ carbon disulphide and dialkyl sulphides, can also be used«,

Suitable as inhibitors of anionic polymerization For example, inorganic acids, carboxylic acid compounds and sulfonic acid compounds, in particular solo with alkaryl, aryl and aralkylsulfonic acid residues, since these compounds are both hydrophilic and

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au oil oleophileBert · included. JIe aminyel bonds suitable eioh ammonia, primary, secondary and tertiary Amines or their salts, which are organic as anions or inorganic acids, carbonate, aryl, alkali

. aryl or aralkyl sulfonic acid residues or alkyl sulfate

Suitable amines are the primary, secondary or tertiary amines or aliphatic or aromatic heterooyol amines, e.g. monoalkylamines, monoalkanolamines, dialkanolamines, piperidine, pyrrolidine or morpholine, alkylenediamines and polyalkylenepolyamines, etc. Particularly preferred all inhibitors of the anion! sohen polymerization raleäuren jmwiiwf _»f v Ammoniumohlerid, Ammoniumealze of mineral, such as sulfuric acid, ammonium p-toluenesulfonate, Ammoniumbeneoleulfonat, ammonium methanesulfonate, Ammoniusalaurylsulfonat, amines or amine salts, s _o B ₀ Methylaminj ithylamin _e, Propylaain ,. Bxtylamin, Amylamin, Amin®p © atess ₈ - Haxylasiin, Allylgmin «'. Dimethyl - * - -. amine, BiäthylaBaiaff IXLpropylamine, Di-eek-'buLtyl * @ min-, '-Mn ~ amylamine _g trimethylamine,

isoljutylaminj, tri-n-amylamine ₍ methyldimethylamine, Ithyleadiandji, propylenediamine, 'Trime'thylenediamine, 1,3 ⁶ -Biaajinol3utan, 1 ", 4 = Diamino" but an »' Pent ^ ämethylene-

diamine ₉ hexamethylenediamine, ootam @ tliylenediamine, spermine, cyclohexylamine ₉ dioyolohexylamine, ". aniline, 2-AmlnO _{" biphenyl <- g} ^^ 4-amino "biphenyl- _s ' ά ■ -liiaphthylamine, V.Sf m = - and P = ToIuUIn ₈ o-3-Iylidine,

p-2-ööBidin.p.-p »6'umidin ₉ . Ps © iiäooumidin ₉ Me-sidin, o-, m- * and p ° -dhlo-ranilin ₉ -'2'1.-5-DiOhIor-enilin, _: . O.-,. m- and ■■ -.p-Kitraaniling '/ o -. and "p-inisidinp sresidine, o- and p-phenetidine 5-nitro-2-bromoxyeniline, benzyl'amine ₉ 35; β-phenylethylaiiin,." Diphenylamine Phenyl -. "'A ■ -naphthyl · -

amine, phenyl-ß-naphthylamine, monomethylaniline, monoethylaniline, tr! phenylamine, dimethyl aniline, diethylaniline, ethylbenzylaniline, ο-, m- and p-phenylenediamine, m- and p-toluenediamine, benzidine, o-toluidine, etc., substituted Amine salts, the alkyl, alkenol, alkaryl or aryl radicals, e.g. B ₀ contain methyl, ethyl, oxyethyl, cyanoethyl, butyl, propyl, benzyl radicals and other radicals. The sulfates, chlorides, bromides, iodides, perchlorates, phosphates, chlorosulfonates, alkyl sulfates, carboxylic acid anions, sulfonic acid anions, aryl sulfonic acid anions and alkaryl sulfonic acid anions may be mentioned as anions of the amines mentioned above p-Toluenesulfonic acid, o-, m- or p-ethyl-taenzenesulfonic acid, o-, m- or p-cumene-sulfonic acid, o-, m- or p-tert-amylbenzenesulfonic acid, o-, m- or p-hexylsenzenesulfonic acid, o ~ Xylene-4-sulfonic acid, p - ^ - lol - ^ - sulfonic acid, m-xylene-4- or -5-sulfonic acid, MeBitylene-2-sulfonic acid, durol-3-sulfonic acid, pentamethylbenzenesulfonic acid, o-dipropylbenzene-4-sulfonic acid , α- or ß-naphthalenesulphonic acid, o-, m- or p-biphenylsulphonic acid and ο -methyl-ß-naphthalenesulphonic acid, methanesulphonic acid, xthanesulphonic acid, laurylsulphonic acid, methylsulphonic acid, ethylsulphuric acid, acetic acid, chlorosulfonic acid, bio, formic acid, acetic acid, triohloress igic acid, hexahydrobenzoic acid, nicotinic acid, oxalic acid, malonic acid, adipic acid, fumaric acid, malic acid, tartaric acid, phthalic acid, phenylacetic acid and the like. In general, any desired amines and anions of the type mentioned above can be combined.

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Since Adipinsäurenitril is industrially hauptsächiioh ■ used for the production of hexamethylenediamine, which serves vonFylon as a starting material "are used as inhibitors of anionisehen polymerization for the hydrodimerization of acrylonitrile hexamethylenediamine or its substituted derivatives, z _o B * the halides, acetylides or alkylated or cyan" ethylated Derivatives or their salts are "particularly" preferred.

Most "preferred as anionic inhibitors Polymerization are sulfuric acid, hydrochloric acid, nitric acid, Formic acid, acetic acid, ethanol, methanol, acetylene and its derivatives, methyl, ethyl, Hexyl-, iauryl- and other alkyl mercaptans, Eohlenoxyd, Carbon dioxide, dimethyl sulfide, carbon disulfide, Benzenesulfonic acid, o-, m- or p-toluenesulfonic acid, o-, m- or p-ethylbenzenesulfonic acidj o-, m- or p-oleum sulfonic acid, o-, m- or p-tert-amyl ■ benzenesulfonic acid, o-, m- or p-hexylbenzenesulfonic acid, o- ^ rlol-4-sulfonic acid, p-xylo 1-4-sulfonic acid, m-xylene-4- or -5-sulfonic acid, mesitylene-2-sulfonic acid, Duro1-3-sulfonic acid, pentamethylbenzo1sulfonic acid, o-Dipropylbenzene-4-sulfonic acid, α - or * ß-H "aphthalenesulfonic acid, ο-, m- or p-biphenylsulfonic acid and α-methyl-ii-naphthalenesulfonic acid and those above named amines or amino salts derived from these amines and the aforementioned acid anions

The concentration of the anionic polymerization inhibitor in the aqueous phase of the emulsion depends on the type of inhibitor and can, for example between 10 ppm and 10 pounds · The concentration of the inhibitor in the oil phase of the emulsion can be between 0.01 and 10 Öewo-? I lie «

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To form the emulsion used for electrolysis the abovementioned Beatand parts can be found in can be put together in any desired sequence »

As already mentioned, the electrolysis can be carried out in any conventional electrolysis cells. "The acrylonitrile is dimerized" at a cathode potential of about -1.9 "to -2.0 V. As already mentioned, the electrolyte salt produces the necessary electrical conductivity, but it separates does not come off the cathode at this potential »The electrolysis can thus be carried out by simply passing the electric current between the cathode and anode through the emulsion. However, it has proved advantageous to use an electrolysis cell which comprises separate anode and cathode compartments separated by a diaphragm, and a separate anolyte to use "The anolyte is a mineral acid solution, Z ₀ as hydrochloric acid, sulfuric acid, nitric acid, and Phosphoric acid at a concentration of less than 60 % is preferred, with sulfuric acid being most advantageous. However, it is also possible to use organic acids, for example monoalkylsulfuric acid, or aromatic or aliphatic sulfonic acids or, in general, any acids that easily add hydrogen ions that are consumed at the cathode. The anode can be made of any material . Preference is given to materials that do not corrode due to oxygen, e.g. B ₉ platinum, nickel, Uiokelcyolioid, Duriion, lead or lead alloys, z. B lead-antimony alloys »

The diaphragm, which separates the anode compartment from the cathode compartment, can consist of conventional materials, Z ₉ Bo made of sintered glass, porous plates, fexgamentpa-

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.-. ; ■. ■ .- ":. ■ ... '■.; ■ ^v - 19 -:; ■■■■■■ ■; ν- - ■,. ■:

pier o · dgl * TorBUgsweiee is used as a diaphragm a cation dew Bohmea "bran, used since in this YaIl through the hydroxyl ions formed on the cathode Waeseretoffionen, which are eelaktiv auroh the Kationenaue move the exchange diaphragm out of the anode compartment, quenti- can be neutralized “Particularly suitable is a Xationenauatausohdiaphragmai because it contains sulfone acid groups and Oar!” acid groups, β. Β. • in a diaphragm made of sulfonated styrene-divinyl-tjenzol- Polymers · The Kationenaueohdiaphragm can from homogeneous or heterogeneous type be · Da "at his Use the hydroscyl ions formed in the cathode can be quantitatively neutralized the Pg-Vert Ι «KathodenrauBi must be kept constant.

It is desirable that the cation exchange diaphragm during the flow of current mxs the Waseeretoffionen and not the other components, e. B · the sulphate ions or aorylsitr ± l _s -wom the cathode compartment into the ino - ^: denraumte Wem- äms_ , pu-WeE't i® cathode compartment. .20 ^: ;. Bioh duroh insufficient _: <jtsuto ^ isation - .. changes, which is the consequence of the fact that a small amount of the inione dee salt passes through the diaphragm and discharges electricity at the anode, the emullion can through the addition of acids, B, B. sulfuric acid or toluene-ulfonic acid. Pure the Cathode materials are preferred that have a high Have hydrogen undervoltage, see B, copper, cad * slum, lead, tin, mercury or alloys of these metals. Me bu electrolyzing emulsion is made preferably circulated through the cathode compartment · How already mentioned, it may solvent, e.g., B "acetonitrile, Dioxmn, ithylenglykol, dimethylformamide, Dimathylaeetamiä Xthancl ,, u _e contain the like *.

During electrolysis, the catholyte is maintained the _pH value preferably between about 1 and 10, since this value is exceeded, an excessive formation of BLsoyanäthyläther takes place and Tasi a p _H deposited excessive lowering -value hydrogen at the cathode, is "Preferably, a p_-value 3-9, in particular 3-6" The oil phase in the emulsion, which is supplied to the cathode space is preferably finely dispersed , and the cathodes space should be designed in such a way that the It is possible to maintain an emulsion as fine as possible "- For this purpose, the cathode compartment is advantageously designed in such a way that the emulsion inevitably occurs directed against the cathode at high speed will,

Its horizontal cathode surface is generally unfavorable because of the problems of gas separation. When using multiple inches, it is advisable to provide bi-punched pieces in each electrode space with a fixed distance in each metal electrode space can be quite preserved and turbulent flow is facilitated. Dietetic tubes of the type commonly used between the ion exchange diaphragms Electrodialysis can be used · It is also essential to carry out the anolyte to circulate the anode compartment. Flow velocities between 0.1 and 200 om / sec. Are preferred, preferably from 5 to 100 om / sec »both in the anode compartment and in the cathode compartment ·

The electrolysis can be carried out at any temperature up to the boiling point of the acrylonitrile, but temperatures between 0 and 80 ^° C. are preferred. Temperatures are particularly preferred

009839/2153

between 15 and 8Q ⁰ G, in particular between room temperature and 70 ⁰ Oo The soluble wedge; of acrylonitrile in the aqueous phase of the emulsion naturally increases with increasing temperature

If the temperature is too low, oligomers wont ■ to be educated. If it is too high, there will be education of Bisoyanäthyläther and propionitrile instead. Xiit increasing temperatures, the resistance and so that the power consumption is lower «All these actuators must be taken into account when determining the optimal working conditions o c

The current density can be within wide limits. However, current wires between 3 and 30 A / dm are preferred. Too low currents are to be avoided, since the system costs for the electrolysis cell increase, while on the other hand "if the current density is too high, the electrolysis voltage becomes high and the power consumption increases accordingly, _{or the like}

The in _{electrolysis:} Adipinsäurenitril formed is mainly absorbed by the oil phase of the emulsion and is easily alDtrenntiar ,, example, the emulsion may be withdrawn from the cathode compartment and separated into an oil phase and an aqueous phase and the product of electrolysis from the separated phases, in particular of the oil phase. Part of the aqueous phase separated off as a whole can be converted back into an emulsion by adding more acrylonitrile and fed back into the cathode compartment

The separation of the emulsion, i.e. H. the breakout of the the emulsion running off the cathode compartment can be

009839/2 153

in a known manner, ζ »B. by settling, centrifugal separation, filtration or the like. and duroh heating. B _{9 can be} obtained by distillation, absorption, extraction or the like. In the context of the invention, it is also possible to separate the greater part of the aorylnitrile and adipic acid nitrile by washing the oil phase with water in order to achieve the

• jQ electrolyte salt and the inhibitor of anionic polymerization to remove·

As already mentioned, a much lower concentration is used in the method according to the invention of the aqueous dissolved aorylnitrile than in the case of the

Known processes are used, so that the separation is greatly facilitated. At these lower concentrations it is possible to use conductive salts which are relatively weakly oleophilic and therefore only dissolve in low concentrations in the oil phase. The presence of lower concentration of these salts in the oil phase facilitates the extraction and Yerwendung enables an extraction apparatus with a small number of theoretical plates _o When applying the low concentration of aqueous dissolved acrylonitrile according to the invention, the ratio of formed Adipinsäurenitril to acrylonitrile in the oil phase increases according to whereby the separation of the Adipinsäurenitrils is facilitated acrylonitrile "If gearbei- this way" is dead, the Aorylnitrilmenge, which must be separated from Adipinsäurenitril by distillation, for example, ₉ relatively low, so that the distillation facilitated, and its economic efficiency wirda generally increases can in case of

009839/2153,

τρη quaternary ammonium salts as conductive salts Salae with a total number of carbon atoms, bound to nitrogen, of 10 or less they are viewed as weakly oleophilic. These Salts are therefore preferred as supporting electrolyte salts because at their use, the aarylnitrile sioh only dissolves in a relatively low concentration in the aqueous phase, whereby not only the advantages described above with regard to the product

to divorce and gain, but rather The efficiency and the yield of the electrolysis itself can also be increased. As already mentioned, special solos are preferred, which do not have the solubility of aoryl nitrile in water over 10 öew.-jß and the resolution of more than 5 Jf in the actual aqueous phase of the Do not allow catholytes

If, on the other hand, a high ion concentration of aqueous, dissolved carcass is worked, as was required in the known methods, the separation is cumbersome and difficult and may require multi-stage distractions or larger distillation plants and higher operating costs

in general, in the process according to the invention when using the latholyte emulsion, the contains the oil phase, a separate extraction stage is not required at the beginning to first remove the Separate dissolved olphe.ee from the aqueous solution · As already mentioned, the oil phase can lent be separated. Jfaoh this separation can be the extraction on a single stage, in which the conductive salt and the inhibitor of anionic polymerization be separated from the separated oil phase,

00 9839/2 153 _BAD

be restricted. As already mentioned, this extraction can in many cases be carried out with a simple wash with water, e.g. B. be carried out in a cocurrent or countercurrent column. the Extraction of these salts can also be done with solutions that mainly consist of water, but can also contain acrylonitrile, for example, in a concentration up to saturation. These extraction solutions can then according to the invention in the Catholyte emulsion are converted «.

After the removal of the Leitealees the elec-. trolyseprodukte by fractionation in Adipinsäurenitril, P _r opionitril be separated and the oligomer etc _o · acrylonitrile and Adipineäurenitril natuerIich can according to customary methods, s · B are separated from each other by distillation ₀ ,,

example 1

The electrolysis cell used had a lead cathode with a surface area of 10 cm 10 cm and a lead-antimony anode with the same .area · the

The anode compartment and the cathode compartment were through a cathode

ion exchange diaphragm separated from one sulfonated divinylbene-sol-styrene-butadiene copolymers of 1 mm thickness. The cathode compartment and the The anode compartment of the electrolyzer cell both had one

Length of 10 om and a width of 10 cm. Between

the electrode surface and the diaphragm surface were kept at a distance of 1 mm with the aid of spacer tubes. The anolyte was with a Pump between the anode compartment and the anolyte container circulated, and the emulsion for the cathode compartment

009839/2153

was also used with a pump between the cathode compartment and the catholyte "container circulated as 'Anolyte was a 2N solution of sulfuric acid with a Speed of 30 om / sec circulated »

An emulsion which consisted of 100 parts of a closed aqueous phase and 50 parts of a dispersed oil phase was fed to the cathode compartment and circulated at a flow rate of 30 om / sec. The electrolysis was ^{carried out at 40 0} O with a current of 10 A.

The aqueous phase of the emulsion, which was supplied to the cathode, "consisted of 3.5 $> acrylonitrile, 9.5 # electrolysis product (8.9 # Adipinsäurenitril, 0.24 i> propionitrile, a very small amount SLscyanäthyläther and 0.31 $> Aorylnitrile oligomer), 69.0 $> water, 15.0 i> letrapropylammonium sulfate and 3.5 # hexamethylenediamine-p-toluene sulfonato The Pjj value "was 3 · The oil phase T consisted of 23.7 & acrylonitrile, 64 _S 2 ^ Electrolysis products (60.5 ^ adipic acid nitrile, 1 »6? Ί propionitrile and 2 _f 1 $> aoryl nitrile oligomers) ₉ 9 f> water, 2 fS tetrapropylammonium sulfate and 1 $ hexamethylenediamine-p-toluenesulfonate that were present in the aqueous phase and in the oil phase would not be added at the beginning, but were formed during operation and circulated with derKatholytemulsion "during the electrolysis was acrylonitrile of the running from the cathode compartment emulsion added _o the erh old homogenized emulsion was adjusted to the above-mentioned composition and returned to the cathode compartment. The electrolysis cell was operated in this way for 300 hours.

009839/2153 -

By analyzing the cathode emulsion during this operating time, the percentage selectivity of each product was determined as the ratio of the weight of the acrylonitrile consumed for each product to the total amount of aorylnitrile consumed. This selectivity was 2.5 # for propionitrile, 94 1> for adiponitrile, 3.3 # for Aorylnitriloligomere and 0.2 i "for Bisoyanäthyläther. The emulsion flowing out of the cathode compartment was then removed from the catholyte container and allowed to stand to separate the oil phase. To separate the conductive salt dissolved in this oil phase, the oil phase had to be passed through an extraction column operating continuously in countercurrent?

This extraction column was supplied with water dropwise from above, while the oil phase was supplied from below was introduced · By extracting the oil phase with an amount of water that is only one-fifth the amount of oil phase, it was possible to reduce the amount of the conductive salt contained in the oil phase to less than 0.0 3 # to lower""

The adipic acid nitrile is obtained by distillation of the oil phase from which the salt has been removed »

When the emulsion containing acrylonitrile in the oil phase components was electrolyzed in the manner described above, although the aoryl nitrile concentration in the aqueous phase was less than 5 f> , adiponitrile was formed with high selectivity, and no polymer was formed in the electrolyzing cell. The selectivity to P _r opionitril rose during the long operating period ever "

009839/2153

However, if the experiment described above is repeated using an aqueous solution of acrylonitrile in a concentration of less than 5 % in place of the emulsion, the acrylonitrile becomes almost exclusively converted into propionitrile, while no adiponitrile is formed. When a Acrylonitrile emulsions other than those used in this example, the anionic polymerization contains preventive inhibitor, is electrolyzed, forms calibration in a short operating time, a large amount of polymer at the cathode) the acrylonitrile is converted into propionitrile, the selectivity to Adipineäurenitril increases with Z _e it gradually decreases, and the electrolysis can as a result of polymer formation not to be continued. This is illustrated by Examples 1 * and 1b

■■ - ■■ - example ta

In the slektrolysing cell used in Example 1 the incoming cathode solution was the same Composition for that according to Example 1 used aqueous · phase set with the difference that neither an oil phase was present and neither methylenediamine-p-toluenesulfonate was added to the catholyte solution became · In this case a catholyte from a aqueous aoryl nitrile solution prepared by adding aoryl nitrile the liquid draining from the cathode compartment added iind the oil phase was separated. the The aqueous solution phase obtained was fed to the cathode compartment alone

The other conditions of the electrolysis were the same same as maintained in Example 1 became. The solution entering the cathode compartment

0 0 9 8 3 97 2 15 3 '

was adjusted to the following composition 3> 5 # acrylonitrile, 9.5 1 * of the same electrolysis products of adiponitrile, propionitrile, bisoyanethyl ether and aorylnitriloligomerem, 72.0 # water and 15 ί » Tetrapropylammoniumsulfato this solution, the cathode chamber with a flow rate of 30 om second was supplied /, had a p "value of 3o the electrolysis was performed with a current of 10 a" carried out at a temperature of 40 ⁰ C. the conditions in the anode compartment were the same. as in example 1. from the in the electrolysis consumed acrylonitrile was 91.7 in propionitrile, 8.0 i »in Adipinsäurenitril, 1.0 and 0.2 # in Oligomeree i> in Bisoyanäthyläther converted · When the electrolysis was continued for 200 hours under the same conditions, the polymer was deposited in the cathode compartment , and the selectivity for propionitrile gradually increased, while the selectivity for adiponitrile decreased during the electrolysis «It was thus not m possible to keep the operation of the electrolysis stable for a long time under these conditions

When this experiment was repeated with the difference that 3.5 # hexamethylenediamine p-toluenesulfate were added to the cathode solution, the selectivity was for propionitrile, adiponitrile and bisoyanoethyl ether almost unchanged, but no polymer was found on the cathode and in the cathode compartment itself separated after a long period of operation «

Example 1b

The experiment described in Example 1 was repeated under exactly the same conditions with the

00 9839/2153

■ '■ ■ ..' .. "■." -29 - -. ■ - - ■ -. ■■

Difference that no hexamethylenediamine-p-toluene- - sulfonate was added to the emulsion fed to the cathode compartment

The catholyte emulsion "consisted of 100 parts of an aqueous solution and 30 parts of an oil phase. The aqueous phase of the emulsion, which was fed to the cathode compartment," consisted of 3.5 $> acrylonitrile, 9 _t 5 $> electrolysis products (addpinic acid nitrile, eropionitrile, bisoyanoethyl ether and aorylnitriloligomerem), 71 _s 0 jt barrels and 15.0? S tetrapropylammonium sulfato The Pg value "was 3 © The oil phase of the emulsion introduced into the cathode compartment consisted of 23.7 $> aorylnitrile, 64.2? 6 electrolysis products (adipic acid nitrile, Propionltril and Aorylnitriloligomeres), 9 ^ Wa.sser and 2> 5 $ Tet "propylammoniumsulfat _e Within an electrolysis time of 40 hours, a very large S @ ng @ Aerylnitrilpolymerisat ge-Mldet that the ^z ella Marketers pot te, so that the electrolysis nioht could be continued * Of the acrylonitrile consumed during the electrolysis, $ 95.5 was converted into propionitrile and only $ 4.1.6 into adiponitrile

Example 1 ο

The tests described in Examples 1, 1a and 1 "b were repeated "at Pg 7.6. In each case was-. receive the similar results as in the corresponding example »

Example 2

The goal direction described in Example 1 "included the Tinjrde electrolysing cell. The anode solution was made under the same conditions as

Bine emulsion circulated in Example 1, which consists of 100 parts of the aqueous solution phase and 100 parts of the oil phase ", was fed to the cathode compartment at a flow rate of 50 om / sec.

The aqueous phase of the emulsion, which was fed to the cathode compartment, testing out 2.0 i »acrylonitrile, 5.7 i> Adipinsäurenitril, 0.17 £ propionitrile, a very small amount Biscyanäthyläther, 0.14? C Aorylnitriloli / fgomerem, 71 »9 Ϊ water, 17.0 i» tetraethyl

1Ö ammonium sulfate, 3.1 i> ^, IP-dimethylhexamethylenediamine-p-toluenesulfonate and 100 ppm methyl cellulose. The Pg value was "at 8 _O, the oil phase of the Kathow denraum incoming emulsion consisted of 22.0 # acrylonitrile, 61 $ Adipinsäurenitril, 1.8 # propionitrile, 0.1 f> Bieoyanäthyläther, 1,5 fi Acrylnitriloligomerem, 8 fS water, 3 > tetraethylammonium sulfate and 2 fS Η ", N ¹ -Dimethylhexamethylendiamine-p-toluene sulfonate The electrolysis was carried out with a current of 10 A" at a temperature of 55 ⁰ O. The adipic acid nitrile, propionitrile, the biscyanäthyläther and the aoryl nitrile oligomer in the incoming catholyte were obtained from the liquid drained from the cathode compartment by adding acrylonitrile to the draining catholyte emulsion, adjusting it to the above-mentioned composition and circulating. The electrolysis was carried out for 300 hours. The analysis of the cathode emulsion during this operating period showed selectivity of 2.8 # for propionitrile, 94.5 $ for adipic acid nitrile, 2.3 $ for the aorylnitrile oligomer and 0.2 $> for bisoyanoethyl ether. The emulsion running off from the cathode compartment was drawn off from the catholyte container and allowed to settle in order to separate off the oil phase. In order to separate the dissolved conductive salt from the oil phase, it was operated continuously in countercurrent.

009839/2153

tend «extralition column led ·

In this column, water was added dropwise from above, while the oil phase was supplied from below ·· me amount of ^ eitseizes in the ulphase was lowered by the extraction to less than 0.02 j ", the amount of water one tenth used the amount The adipic acid nitrile is obtained by distillation of the Ulphae separated from the conductive salt.

When the emulsion, the acrylonitrile in an ulphase was electrolyzed in this way, "formed adiponitrile with high selectivity, although the aoryl nitrile concentration in the aqueous Solution was below £ 5 and no polymer was in

dec electrolysis cell formed. Am increase in the selectivity of propionitrile due to the polymer separation the duration of the experiment never occurred at the cathode without disturbance. If, on the other hand, the aqueous solution of Acrylonitrile in concentration less than $ 5

j§} was electrolyzed, it was found that the aorylni-

tril almost exclusively converted into propionitrile and no adiponitrile was formed without Büoksioht on the presence of the Ν, Ν ¹ -dimethylhexamethylene-p-toluenesulfonate serving as an anion inhibitor.

If an aoryl nitrile emulsion not containing the anionic polymerization inhibitor is applied to the electrolyzed in the manner described in this example a large amount of polymer formed in the cathode compartment within a short period of operation,

so that the acrylonitrile as a result of the deposition of Polymer at the cathode is converted into propionitrile, the selectivity of adiponitrile is low and electrolysis as a result of "polymer formation."

could not be continued »The same results were obtained when the examples at Pg 3 »8 were repeated.

Example 3

The electrolysis cell described in Example 1 "was · A 2N sulfuric acid solution was used as the anode solution with a flow rate of 30 om / sec. circulated

Sem cathode compartment was fed an emulsion consisting of 50 parts of a continuous aqueous phase and 100 parts of a disperse oil phase and circulated at a flow rate of 30 om / Seke and electrolyzed at 4O ⁰ C and 15 A was ₀

You aqueous phase of the emulsion, which was * space supplied to the cathode, consisted of 4 # acrylonitrile, 15.6 $ Adipinsäurenitril, 0.7 # propionitrile, a very small amount Biscyanäthylather 0.7 $> Aorylnitriloligomerem, 61.0 £ Water, 17.0 # tetraethylammonium p-toluenesulfonate and 1.0 4> cyanoethylated hexamethylenediamine p-toluenesulfonate and had a Pg value of 4.9. They oil phase consisted of 16.4 5 * acrylonitrile, 64.0 f> Adipinsäurenitril, 2.8 # propionitrile, 2.8 i »Aorylnitriloligom.erem, 7 _f 0 i" Water, 4- # tetraethylammonium-p-toluenesulfonate and 3 Iyanethylated hexamethylenediamine-p-toluenesulfonate. The adipic acid nitrile, propionitrile, bio-ethyl ether and acrylonitrile oligomer in the emulsion were electrolysis products that were circulated. During the electrolysis, acrylonitrile became the emulsion draining from the cathode compartment

30- added you received, to the above

009039/2113

- 33 - . ■■

The homogenized emulsion adjusted to the composition was electrolyzed for 300 hours. The analysis of the cathode emulsion during this period of operation showed the following selectivity for each product: 4.0 $ for propionitrile, 92.0 # for adiponitrile, 4.0.6 for aorylnitrile oligomer and 0.1 # for Bisoyana ethyl ether. '

The emulsion running down from the cathode compartment was drawn off from the catholyte container and allowed to settle to separate the oil phase.A continuously operating countercurrent extraction column was used to separate the egg salt dissolved in this oil phase.O In this column, water was added dropwise from Olsen, while the oil phase was introduced from below was * Duroh Bxtraktiom the oil phase with an amount of water of only 1/5 the amount öäs? oil phase was the Grehalt / ί to iieitsalz in 3 Ölpässa to less than 0.03 i »be reduced. ·

The adipic acid nitrile was obtained through distillation of the ■ treated oil phase *

When the acrylonitrile-containing emulsion on the in this example T3esohrie "bene way electrolyzed would, Mldete sioh adipic acid nitrile with high selectivity, although the concentration of Aoryl nitrile in the aqueous solution is less than 5% "cheat a Pölymer's message in the electrolysis cell did not take place and the selectivity increased Propionitrile rose during the long operating period niohto '

If, on the other hand, an aqueous solution of acrylonitrile in

was electrolyzed at a concentration of less than 5 J *, the acrylonitrile was almost exclusively converted to propionitrile »Adipic acid _{nitrile was not formed o} When an acrylonitrile-containing emulsion, which did not contain the inhibitor preventing the anionic polymerization, was electrolyzed, a large amount of polymer deposited the cathode off. After a short period of operation, the acrylonitrile was mainly converted into propionitrile, and the electrolysis could not be continued. Changing the p ^ value of the catholyte to 3 »8 did not result in any significant change in the above-mentioned results

Example 4

The electrolysis cell used was designed similarly to the electrolysis cell described in Example 1. Its cathode consisted of pure lead and. had a surface area of 10 cm × 10 cm. The anode was made of a lead-antimony alloy and had the same surface area. The cell was 10 cm long and 10 cm wide. The distance between the cation exchange diaphragm and the electrode was 2 mm ⁰ O and a current of 10 A.

The aqueous phase of the emulsion, which was introduced into the cathode compartment consisted of 3 »$ 1> acrylonitrile, 4.9 £ Adipinsäurenitril, 75.2 & water 18.0 Ji Tetraäthylammoniumsulfat and 3.5 f> hexamethylenediamine-p-

009839/2153

toluenesulfonate · The p value was _fi 5 ο The oil phase "consisted of 56 i> acrylonitrile, 56.0 i" Adipinsäurenitril, 6 Ji water, 1 ji letreäthylajnmoniumsulfat and 1 # hexamethylene diamine p-toluene sulfonate. During the electrolysis was in the cathode compartment incoming emulsion "in the above composition held It was 6 hours guided me selectivity! electrolysis" contributed 8.3 $ for propionitrile and 85.0 i "for Adipinsäurenitrilo

■ JO - If the emulsion containing acrylonitrile in the oil phase components is based on the one in this example. sohriebene manner elektrolyeiert, adipic acid was iaitril formed with high selectivity, although the KoaiBeiatration of Aorylnitril in the aqueous solution was less than 5 i>. Polymers were not formed, and the selectivity to propionitrile not increased even after a long operating time _o

If, on the other hand, an aqueous solution of aorylnitrile with a concentration of less than 5 _{% was} electrolyzed, the aorylnitrile was converted almost exclusively into propionitrile and adipic acid nitrile was not formed in spite of the presence of the ionic polymerisation inhibitor si on was electrolyzed by acrylonitrile, which did not contain the polymerization inhibitor used in this example, a large amount of polymer was formed at the cathode within a short operating time, which increased the selectivity to propionitrile and ultimately prevented continuation of the electrolysis.

OÖ9 6 39/21 !!

Example 5

The Eiektrolysierzelle described in Example 1 was used, the anode jedooh from Fiatin existed and a surface area of 10 om χ had cm 10 consisted while the cathode of a 1 $> antimony lead alloy containing and had the same surface "As the anode solution was a 0, 5N sulfuric acid solution used and circulated at a flow rate of 40 om / sec "

As catholyte an emulsion file 100 a closed aqueous phase, and 50 parts of a disperse oil phase used was, and was electrolyzed at a flow rate of 15 om / sec "and circulated at 37 ⁰ C and a current of 10 A"

They aqueous phase of the emulsion fed to the cathode compartment consisted of 2.5 i »acrylonitrile, 8.5 $> Adipinsäurenitril, 68.5 1> water, 17.0 i" Tetraäthylammoniumsulfat and 3.5 H triethylamine and Triäthylaminnaphthalinsulfonat "Der p" - value was 8 "the Ulphase of the incoming to the cathode compartment emulsion consisted of 20.3 # acrylonitrile, 62.2 i" Adipinsäurenitril, 6.5 f> of water, 2.0 1 »Tetraäthylammoniumäthylsulfat and 2.0 i» triethylamine and Triäthylaminnaphthalinsulfonat ·

The electrolysis was performed 250 hours, while the entering into the cathode compartment emulsion was kept at the above composition · Analysis of the cathode emulsion resulted in a selectivity of 4.9 i> for propionitrile, 90.0) 6 - ■ -for Adipinsäurenitril, 5 , 0 # for acrylonitrile oligo-

009839721

meres ima OjI 56 for Bisoyaoathylathei ¹ ·

Wean the emulsion * which contained acrylonitrile in the oil phase components to that in this. Example "was electrolyzed in a way, adipic acid nitrile was formed with high selectivity, although the concentration of acrylonitrile in the aqueous phase was below 5 $ . Polymers were not formed and the selectivity to propionitrile did not increase even after a long period of operation.

Example 6

• JÖ The electrolysis cell described in Example T "was used, but its cathode is made of a lead-antimony alloy "and had an ole surface of 10 om 2 10 om, and its anode was made of a lead-antimony alloy "stands and the same surface had »An in-sulfuric acid solution was used as aaodeal solution solution with a collision velocity of 30 cm / Sec »circulated«

Me Bmulsion _t composed of 100% of an aqueous phase and an oil phase $ 30 "was identificati circulated at a flow rate of 10 pm / Seko and" electrolyzed at 50 ^Q E with a current of 10 A ·

aqueous phase of the emulsion einläutenden in the cathode compartment "consisted of 3.1 1» acrylonitrile, Adipinsäurenitril, 71.4 & water, 17 »0 $ Irimethyläthylammoniumäthylsulfat and 3.5 $> Iri" butylaminsul-. · did your _pH value "was 3" The oil phase of the incoming to the cathode compartment emulsion components from Aorylnitrilt 46 $ Adipinsäurenitril, 6 56 Water »5 | O i * frimethyläthylamiaoniumsultat and 1 gO S

butylamine sulfate. The electrolysis was carried out for 24 hours. During this time, the emulsion flowing into the cathode compartment was kept to the above-mentioned composition. It gave a selectivity of 13 # of propionitrile, 83 ₁ 0 i "for Adi pin Saur enitril, 4.0 $> for Aorylnitriloligomeres and 0.1 for $ Bisoyanäthyläthero during operation analysis carried out

If the emulsion containing acrylonitrile in the oil phase, on the one described in this example Electrolyzed way, adiponitrile was formed with high selectivity, although the concentration of acrylonitrile in the aqueous solution was less than 5 # · Polymers were not formed, and the selectivity eu propionitrile never increased.

Example 7

The electrolysis cell described in Example 1 was used. A 0.5N sulfuric acid was used as the anolyte e solution with a flow rate of 10 cm / sec. circulated »

An emulsion, which consisted of 50 parts of an aqueous phase and 100 parts of an oil phase, was fed to the cathode compartment and circulated at a flow rate of 30 om / sec and ^{electrolyzed at 40 °} C. with a current of 10 A The emulsion fed to the cathode compartment consisted of 4 $ * acrylonitrile, 1t _t 8 $> adipic acid nitrile, 1.6 56 Pj-opionitrile, a very small amount of bisoyanoethyl ether, 0.6 ^ i acrylonitrile oligomer _a 61.0 %> water, 18.0 $> letramethylammo-

nium p-toluenesulfonates, 2,5 i "Biäthylaminlaurylsulfat and 0.5 Ji a" naphthylamine-p-töluolsulfonat. The P ^ value was 3 · The oil phase of the emulsion entering the cathode compartment "consisted of 2O ₉ O i» acrylonitrile, 58.0 Ji adipic acid nitrile, 8.1 + propionitrile, 2.8 Jt Aorylnitriloligomerem, 6 i "of water, 3.0 j> letramethylammonium p-toluenesulfonate, 1.5 1 * Dimethylaminlaurylsulfat and 0.5 ^ ff-liaplithylamin-p-toluenesulfonate The _e Adipinsäurenitril, propionitrile, the Bisoyan ethyl ether and the aorylnitrile oligomer in the aqueous In the gene phase and in the oil phase, circulating electrolysis products were β

While the electrolysis was being carried out, the in the cathodic room! at the end of the emulsion is called the before composition-mentioned "The homogenized held by the addition of acrylonitrile incoming emulsion was alektrolyeiert 24 hours. Analysis during operation gave a selectivity of £ 11.7 for propionitrile, £ 84.0 for adiponitrile, £ 4.1 for Aorylnitriloligo / meres and 0.2 ^ for Bisoyanäthyläther · The emulsion running off from the cathode compartment was withdrawn from the catholic container and left to separate the oil phase. That in this Oil phase dissolved conductive salt was in a continuous lioh working countercurrent extraction column separates · This extraction column became water added drop by drop from above. The oil phase was introduced below. Duroh extraction of the oil phase with an amount of water that is only 1/5 the amount of the oil phase was, the amount of conductive salt in the oil phase could be reduced to less than 0.03 5t.

009839/2153

The adipic acid nitrile was obtained by distillation of the oil phase treated in this way .

Example 8

The electrolysis cell described in Example 1 was used. 0 _f 5N sulfuric acid was introduced as the anolyte solution and circulated at a flow rate of 30 om / sec.

An emulsion, which consisted of 100 ropes of an aqueous phase and 50 ropes of an oil phase, was thrown through the cathode compartment at a flow rate of 30 om / sec. circulated and ^{electrolyzed at 30 0} C with a current of 10 A

The aqueous phase of the incoming to the cathode compartment emulsion consisted of 2 j £ acrylonitrile, 6 f> Adipineäurenitril, 70.5 $> water, 11.0 f> Trimethylbenzylammoniumsulfat and 2 ₉ 5%> Monomethylaminaoetat _β your Pg value was 3 x the oil phase of the incoming to the cathode compartment Bmulsion consisted of 22 i »acrylonitrile, 60.0 i> Adipinsäurenitril, 6 <£ water, 3.0 i · Trimethylbenzylainmoniumsulfat and 2.0%> Monomethylaminaoetat ·

IMLe emulsion running into the cathode compartment was electrolyzed for 24 hours. During this time it was kept at the above-mentioned composition. The analysis during the operation revealed a selectivity of 5.3 + for Sropionitril, 89.5 $ for "Adipinsäurenitril, 4.5 + 0.2 for Aorylnitriloligomeres and io for Bieoyanäthyläthero

009839/2163

Example 9

The electrolysis cell described in Example 1 was used. The anolyte became a 0.9N sulfuric acid solution with a flow rate from 60 om / sec. circulated "

An emulsion consisting of an aqueous Baase ropes and 50 an oil phase consisting of 100 parts, was fed to the cathode chamber and electrolyzed with a Strb'mungsgeschwindigkeit 60 om / sec _o circulated and at 50 G ⁰ at a current of 10 A _o

'The aqueous phase of the incoming to the Eathodenraum emulsion consisted of 4.0 $> acrylonitrile, 12.7 $> Adipinsäurenitril, 56.5 ^ water, 12.0 i> Methyltriäthylammonium p-toluenesulfonate and 0.5 $ F, Li ^f -Di-

methylhexamethylenediamine latryl sulphato your Ρττ value. The 4o was ölplias® the incoming RUs in Eathodenraum emulsion mStand of 18.7 $> Aorylnitril, 59 »4 & # 8 Adipinsäurenitrilif water, 6 ^ Methyltriäthylarmnonium p-toluenesulfonate and 2 i" Έ _$ U * -Dimethylhexamethylendi amini aur yl sul f at "the electrolysis was stirred for 15 hours.The ₀ During this time, the incoming into the cathode compartment emulsion at the above composition was maintained. The selectivity was 3.3 $> for propionitrile, 91.0 # AdipinsäurenitrilV for 5.2 <fi for Acrylnitriloligo- · mer and 0> 5 fi for Biscyanäthylätherp

Example 10

The electrolysis cell described in Example 1 was used * A Ι, Οη-sulfuric acid solution was added as an anolyte and with a flow speed of 30 om / sec * circulated *

Its emulsion, which consisted of 100 ropes of an aqueous phase and 50 parts of an oil phase, was fed to the cathode compartment and circulated at a flow rate of 30 om / sec and ^{electrolyzed at 42 °} C. and a current of 10 A to the cathode compartment incoming emulsion "consisted of 3.5 Ji acrylonitrile, 4" 1? t Adipinsäurenltril, 71.5 i "water, 17.0 i" Tetraäthylammo- niumsulfat and 3.5 # ammonium p-toluene sulfonate · your

"Was 3. The oil phase of the incoming to the cathode compartment emulsion" • JO Pg value consisted of 39 fi acrylonitrile, 46.5 i> Adipinsäurenitril, 6.1 f> water, 2 # 2 $ 5Betraäthylammoniumsulfat and ammonium p-toluenesulfonate nat "electrolysis was 24 hours performed" during this time, the incoming into the cathode compartment emulsion was 5.0 "in the above composition held. the selectivity" was 3.5 $> for P _r opionitril, 91.3 $ for Adipinsäurenitril, # for aoryl nitrile oligomers and 0.2 #

for biscyanoethyl ether

• Example 11

The electrolysis cell described in Example 1 was used A 0.5N solution of sulfuric acid was used as the anolyte with a flow rate of 30 om / sec. circulated »

An emulsion which consisted of 100 parts of an aqueous phase and 50 parts of an oil phase "was fed to the cathode compartment and circulated at a flow rate of 50 cm / sec. And" was ^{electrolyzed at 40 °} C. with a current of 10 A.

~> v The aqueous phase of the emulsion introduced into the cathode compartment consisted of 4.5 f> acrylonitrile, 10.1? 6

000839/2153

Adipic acid nitrile, 55.2 pounds of water, 14.0 + tetraethylaimaonium p-toluenesulfonate and 0.2 f> p-ioluenesulfonic acid. Its p _H - ¥ ert "was 2.4. The oil phase of the emulsion entering the cathode compartment" consisted of 24 i » Acrylonitrile, 54.7 £ Adipinsäurenitril, 7 S * water, 7 ^ i Tetreäthylaainoniuia-p-tolujolsulfonat and 0.1 i »p-Ioluolsulfonat · The electrolysis was 24 hours filhrt dureng ·. During this time, the column ion entering the cathode compartment became "in the above said composition held · The analysis showed a selectivity τοη $ 5.3 for propionitrile, 88.2 + for Adipineäurenitril, 6.4 £ for Aorylnitriloligomeree and O ₈ 1 ft for BLsoyasäthyläther.

The "mentioned above" in this example is repeated using oxalic acid, acetic acid and sulphuric acid instead of p-toluenesulphonic acid. In each case, adiponitrile is formed with high selectivity.

Example 12

See example 1 / described slekirolyzing cell was used. A 1N solsulfuric acid solution was added to the solution and circulated at a flow rate of 10 ci ^ Beke.

Sine Bmuleion, which consisted of 100 parts of an aqueous phase and 50 parts of an oil phase, "was fed to the cathode compartment and circulated at a flow rate of 60 o ^ / sec. And" ^{electrolyzed at 35 0} G and a current of 10 A.

The aqueous phase introduced into the cathode compartment emulsion consisted of 2.0 fC Aorylnitril, 5.1> Adipinsäurenitril, 75.0 + water, f7 fi Tetra

methylammoniumbenzolsulfonat and 0.1 $> carbon disulfide, "Your p _H value" θ was _β, the oil phase introduced into the cathode compartment Emulsion "consisted of 22" 6 ^ acrylonitrile, 58.4 + Adipinsäurenitril, 6.5 i »Waseer, 3.0 f tetramethylammonium benzene sulfonate and 0.2 ^ carbon disulfide6 The electrolysis was carried out for 24 hours. During this time, the emulsion entering the cathode compartment was "kept at the above composition." The analysis showed a selectivity of 6.8 % for propionitrile, 86 .0 $ for adiponitrile, 7.0 i> for aoryl nitrile oligomer and 0.1 f> for bisoyate ethyl ether.

When repeating the "loaded" • J5 recent attempts using carbonyl sulfide or, carbon oxide instead of carbon disulfide adiponitrile is formed from acrylonitrile with high selectivity.

When the electrolysis described in this example using acetylene compounds instead of 0OS and CS as inhibitors of anionic polymerization was carried out, adiponitrile could be obtained in high yield from acrylonitrile without formation made of polymer.

Example 13

The electrolysis cell used was similar to that described in Example T, with the difference that the cathode consisted of a lead-antimony alloy instead of lead and the anolyte was a 0.5N sulfur alloy. acid solution at a flow rate of 30 om / sec. was circulated _o An emulsion that made

0098 39/2153

TOO T rush an aqueous phase and from 50 parts of an oil phase "was, the cathode compartment was fed with a flow rate of 30 om / sec-circulated and at 5O ⁰ O with a current of 10 A elektrolysierto

The aqueous phase introduced into the cathode compartment emulsion "be st and 2 $ acrylonitrile, $ 6> electrolysis product (containing 5.7 i> Adipinsäurenitril, 0.2 fi propionitrile, a trace amount of ice

> | O \ cyanäthyläther and $ 0.2> Aorylnitriloligomeres), 71 "5 i» Water, 17.0 fi Tetraäthylammoniumsulfat and 3f5 Φ oyanäthyliertem hexamethylene diamine p-toluenesulfonate "You p _H" irert "was 3 _O XfcLe oil phase in this. Emulsion consists of 22 # aorylnitrile, 66 $ electrolysis product ("consisting of 62 _t t $> adipic acid nitrile, 1.2 i * propionitrile and 1.7 ^ acrylonitrile oligomers), 7 $ water, 5 _t o ^ ^ etraäthylaEanoniumsulfat and 2? S cyanäthylierteiE Hex ^ aethylenediamine-p-toluenesulfonat »Bas adipic acid nitrile, propionitrile, the bisoyan-

2Q ethyl ether and the acrylonitrile oligomer in the aqueous Phase and in the oil phase were electrolysis products *

During the electrolysis, aoryl nitrile became the the emulsion running off the cathode compartment was added. the

25. The emulsion obtained was applied to the above

2UBammensetzurEg adjusted and homogenized "" The electrolysis was 3QQ hours duröhgeführt · Analysis of Kathadenemulsion during this Betriebssseit gave a selectivity of ^% $ 3 for propionitrile, 94 _t0 $ for Adipinsäurenitril _t 2 ^ 5 £ fiir

riloligjKaeres and Q, 2j * for m & oyanäthyl-ÜEfce from the cathode chamber draining emulsion was from the Eathöljrtbenäli? deducted wta, to

separation of the oil phase left to stand. The electrolytic salt dissolved in the oil phase was removed in a continuously operating countercurrent extraction column. In this extraction column of water was added from the top and the oil phase · introduced from below amount of the oil phase containing conductive salt of ölphaee was reduced to less than 0.03 1 "in the extraction with a water volume of only 1/6 of the crowd.

The adiponitrile was made by distillation obtained from the oil phase treated in this way »

Example 15a

The experiment described in Example 13 "was repeated with the exception that no hexamethylenediamine. P-toluenesulfonate was added and an aqueous aorylnitrile solution was used as the catholyte, which was achieved by adding acrylonitrile to the liquid draining from the cathode compartment after the The catholyte was thus a homogeneous aqueous solution and not an emulsion o The other conditions of the electrolysis were the same as in Example 125. The solution flowing into the cathode compartment was adjusted so that it was 6 <£ electrolysis product ("consisting of Acrylonitrile, adipic acid nitrile, eropionitrile * bioyan ethyl ether and aorylnitrile oligomer), 75 $ water and % 3 & Eetrapropylammoniumsulfat contained "It had a p _a ~ value of 3" and was supplied to the cathode chamber with a - S ^ romanization rate of 30 om / sec. » electrolysis was mi-fe a power Ύοη 10 a "at a! temperature of 5 NC ° ß durchgefSiirt _e the conditions i Ano the room were the same as in both

Game 13. The selectivity, "based on the acrylonitrile consumed duroh the electrolysis," was 91.8 i> for Ppopionitril, 8.0 5 "for AdipinsäUEenitril, 1.0 # for Oligomeree and 0.2 56 for Bisoyanäthyläther · If the Electrolysis was continued under the same conditions for 200 hours, polymer was deposited in the cathode compartment, and the selectivity for propionitrile gradually increased during the electrolysis, while the selectivity for adiponitrile fell to keep stable for a long time

However, when 3 * 5 i "oyanäthyliertes Hexamethylendiaminp-toluoleulfonat the Katholytlöeung added thereto, was even after long periods of operation no polymer deposited at the cathode and in Eathodcnraum"

Example 13h

The experiment described in Example 13 was repeated with the difference that there was no hexamethylenediamine p-toluenesulfonate supplied to the cathode compartment Emulsion was added

Bie aqueous phase of the incoming to the cathode compartment emulsion thus consisted of 2 # acrylonitrile, 6 ji Elektrolyeeprodukten (Adipinsäurenitril, propionitrile, Biecyanäthyläther and Aorylnitriloligomeres), 75 ^ Lasser and 17 »ß $ Tetraäthylammoniumsulfat" BLe oil phase thus consisted of 22 96 acrylonitrile, 66 t Electrolysis products (adipic acid nitrile, propionitrile and aorylnitrile oligomers), 7 1 » water and 5 ^ tetraethylanmonium sulphate 0 During an electrolysis time of 40 hours aiurde 'a very

'009839/2153

large amount of acrylonitrile polymer formed. From the duroh electrolysis consumed acrylonitrile 95.5 $ were in propionitrile and converted only 4.1 i> in Adipineäurenitril ·

Example 14

The electrolysis cell described in Example 13 was used. A 2N sulfuric acid solution with a flow rate of 30 om / sec circulated.

The aqueous phase introduced into the cathode compartment Emulsion "consisted of 4 i> acrylonitrile, 10.2 i» adipic pinsäurenitril, 1.1 i »propionitrile, a very small amount Bisoyanäthyläther, 0.7 # Aorylnitriloligomerem, 63.0 i" water 18.0 i »tetramethylammonium toluenesulfonate, 3.0 i dimethyl sulfate and 0.1 amini auryl i" α-naphthylamines was your Pg value 3. The

ulphase consisted aue 22.0 + acrylonitrile, 56.0 i »adipic> pinsäurenitril, 6.2 i» propionitrile, 3.6 i »Aorylnitriloligomerem, 6 i * of water, 4 f Tetramethylammoniump-toluenesulfonate, 2 H ni Dimethylnmi auryl sulfate and 0.3 j α-haphthylamine. The adipic acid nitrile, propionitrile, the cyanoethyl ether and the aoryl nitrile oligomer were electrolysis products

The leading electrolysis process was acrylonitrile Cathode space draining emulsion added. Which he The emulsion held was adjusted to the above-mentioned composition and homogenized. The electrolysis was carried out for 24 hours. The analysis of the cathode emulsion during this operating time showed a selectivity of 9 ₉ 4 & for propio- nitrile, 85.0 i> for adiponitrile, $ 5.5 for

009 839/2153

1615067

Acrylonitrile oligomer and 0.1% for biscyanoethyl ether. The emulsion running off from the cathode compartment was drawn off from the catholyte container and left to stand to separate the oil phase. To separate the conductive salt dissolved in the oil phase, the oil phase was passed through a continuously operating countercurrent extraction column. The water was introduced dropwise into this extraction column from above and the oil phase from below. The amount of conductive salt contained in the oil phase was reduced to less than 0.03 % by the extraction, water being used in an amount of only 1/8 the amount of the oil phase.

The adipic acid nitrile was obtained by distillation of the treated oil phase «,

Example 15 .

■ each · The electrolysis cell described in Example 13 was used. An In-sulfuric acid solution was circulated as anolyte at a flow rate of 30 C ¹ '/ sec.

An emulsion consisting of 100 parts of an aqueous 2q phase and 50 parts of an oil phase consisted used as a catholyte and with a flow rate of 30 cm / sec. circulated and "at 45 C 'Electrolyzed with a current of 10 A "

The aqueous phase of the emulsion entering the cathode compartment consisted of 4% acrylonitrile, 10.1 γό adiponitrile , 0.3 % propionitrile, a very small amount of biscyanoethyl ether, 0.3 % acrylonitrilollgumereta, oü, i> * $ water, 17.0 % Tetrapropylammoniumisulfat and 3.5 % Anirrioniumbenzolsulfonat, your p "-

009839/2153

The value was 7.5 o The oil phase of the emulsion "consisted of 24 I> acrylonitrile, 59 I> adipic acid nitrile, 1.9 # propionitrile, 17 # aoryl nitrile oligomers, 9 $> water, 2 # letrapropylammonium sulphate and 1 # ammonium ptoluene sulphonate. Propionitrile, bisyanethyl ether and the aorylnitrile oligomer in the aqueous phase and in the oil phase were recycled electrolysis products.

During the electrolysis, the emulsion entering the cathode compartment was kept in the above composition by adding aoryl nitrile and was electrolyzed for 24 hours. The analysis showed a selectivity of $ 3.0 for propionitrile, $ 92.0 for adiponitrile, 2.6 ? έ for aorylnitrile oligomer and 0.2 # for biscyanoethyl ether "The emulsion running off the cathode was withdrawn from the catholyte container and allowed to stand to separate the oil phase. The oil phase was worked up in the manner described in Example 13"

Example 16

The electrolysis cell described in Example 13 was used. 2N-sulfuric acid was used as the anolyte solution fed and at a flow rate of 30 cm / sec. overturned

In the cathode compartment was sine emulsion consisting of 100 parts of an aqueous phase and $ fö 50 parts of an oil phase consisted, introduced with a flow rate of 50 CFFI / S.ek »circulated and at 30 ⁰ O with- a current of 10 Ä electrolyzed ·

009839/2153 BAD or.ginal

• - 51 -,

Pie aqueous phase introduced in the Kathodenxaum emulsion consisted of 2.0 # Aory Adipineaurenitril, 74 * 7 i> water, 17 »0 i" letraäthylammoniumsulfat, residual carbon disulfide, "You P was ¯ _n 3 · consisted The oil phase of the emulsion" from 22 ίί aoryl nitrile _r 64 _t 6 Ii adipic acid nitrile, 6.5 i water, 2.1 ^ tetraethylammonium sulfate and 0.3 ^ carbon disulfide.

BLe electrolysis was carried out for 3 hours. The duroh electrolysis consumed acrylonitrile was below 3.3 i> in propionitrile, 95.6 ji in Adipinsäurenitril, 2.7> ί in Aorylnitriloligomeres and 0.2 i "in Biecyanäthyläther converted.

When performing the electrolysis under the same conditions, but using 0OS, 00 and aoetylene compounds instead of carbon disulfide, worda also adipic acid nitrile with high yield on A © j? yLait2fil. without formation of Polyaerate formed »>

Example 17 You can see the slectrolysing cell shown in Example 13

was used. As anolyte, a 0.5N soulfuric acid solution was introduced with a flow rate of 30 <u / 8ek. overturned

An emulsion phase consisting of 100 parts of an aqueous phase composition mentioned below and 50 umi ropes of an oil of the following composition was, was introduced into the cathode compartment at a flow rate of 60 cm / sec. circulated and at 40 ⁰ C with a stream

0 0 9839/2153

■ j?

- 52 ^

electrolyzed by 10 A. The aqueous phase introduced into the cathode compartment emulsion consisted of 4 # acrylonitrile, 4.4 + Adipinsäurenitril, 0.6 # propionitrile, 0.2 96 oligomer, 55.6 <f> water, 35.0 i »tetramethyl ammonium methyl sulfate, and 0, 2 # p-toluenesulfonic your ^ p value "was 2.4. the oil phase of the emulsion consisted of 40 56 acrylonitrile, 44 # Adipinsäurenitril, 6 # water, 2.0 $> tetramethyl ammonium sulfate, and 0.1 i» p-Toluolsulfonsäureo

The electrolysis was carried out for 4 hours. The selectivity Taetrug 11.4 f> for propionitrile, 85.0? S for Adipinsäurenitril, 3.5 and 0.1 # for Aorylnitriloligomeres ^ -for Bisoyanäthyläther, "based on the power consumed by the electrolysis of acrylonitrile,

If the electrolysis is repeated among the in this. Example "conditions where however, if oxalic acid or sulfuric acid are used instead of p-toluene sulfonic acid, adipic acid nitrile is used obtained in high yield without polymer formation.

Example 18

The electrolyzer cell described in Example 13 was used. The anolyte is a 2n-Sohwefelsäurelösung at a flow rate of 30 cm / sec _e was circulated,

An emulsion, which consisted of 100 parts of an aqueous phase and 50 parts of an oil phase, was fed to the cathode compartment and circulated at a flow rate of 60 cm / sec and ^{electrolyzed at 40 °} C. with a current of 5 A.

0 0 9 8 3 9/2 1 B 3

The aqueous phase of the emulsion Kathodenraum.eingeführten "consisted of 4 $ acrylonitrile, 15.2 # Adipinsäurenitril, 0, 7 #Propionitril, a trace amount Bisoyanatliylather *, 1.0 f6 Aörylnitriloligomerem, 68.0 and 18.0 96Wasser i " Tetraäthylammonium-p-toluolsulfbnate your ρ -value" was δ ", The oil phase of the emulsion was made up of 17.0 ^ aoryinitrile, 64.0 # adipic acid nitrile, 3.1 $> propionitrile, 4.3 $> aorylnitrile oligomer, 6 $ water and 5.5 96% tetraethylammonium-p-sulfonate The adipic acid nitrile, propionitrile, the bisoyano ethyl ether and the aoryl nitrile oligomer were recycled electrolysis products ":

During the electrolysis, the emulsion entering the cathode compartment was kept at the above-mentioned composition by adding aoryinitrile. The electrolysis was carried out for 10 hours o The analysis resulted in a selectivity of 4.3 ^ for propionitrile, 89.5 $> for adiponitrile , "; 6.0 ^ for aorylnitrile oligoi ^ eres and 0.2 <$> for bisoyane ethyl ether working ^ countercurrent extraction column used. Water was introduced into this extraction column drop by drop from above and the oil phase from below o By extracting the oil phase with an amount of water of only 1/8 the amount of the oil phase, the amount of conductive salt contained in the oil phase could be reduced to less than 0.03-5 o

The adipic acid nitrile / was by distillation of the oil phase treated in this way wonν

009 8 39/21 S3

Example 19

The electrolysis cell described in Example 13 "was used. A 0 _f 5N sulfuric acid solution was fed in as the anolyte and was" circulated "at a flow rate of 10 om / sec.

An emulsion, an aqueous phase, and 50 parts of an oil phase consisting of 100 parts "consisted was introduced into the cathode compartment and with a flow rate of 30 om / sec _o circulated and" electrolyzed at 50 ⁰ C with a current of 15 A "

The aqueous phase introduced into the cathode compartment Emulsion "consisted of 4.5 $> acrylonitrile, 7" i 5 "Adipinsäurenitril, 77.0 and 11.0 # Water 56 potassium" benzenesulfonate. Their p ^ value "was 3ο The oil phase of the emulsion" consisted of 34 f> acrylonitrile, 57 $> adi-

• Pin acid nitrile, 6 $> water and 3% potassium benzene sulfonate »The emulsion was electrolyzed for 10 hours and thereby returned to the cathode compartment in a circuit. The selectivity "was 9.3 # P _r opionitril, 80.5 ^ for Adipinsäurenitril, 10.1% for Aorylnitriloligomeres uni0,1 i" for Bisoyanäthyläther, "based on the power consumed by the electrolysis acrylonitrile ,, The same result was obtained if ammonium benzenesulfonate was used instead of potassium phenylenesulfonate "in the Versuoh described in this example" »

Example 20

The electrolyzer cell used in Example 13 was used used. A 0.5N sulfuric acid was used as the anolyte solution supplied and with a flow rate circulated by 30 om / seco

009839/2153

An emulsion, which consisted of 100 parts of an aqueous phase and 50 parts of an oil phase, was introduced into the cathode compartment and circulated at a flow rate τοη 50 om / sec and electrolyzed at 40 ⁰ O with a current τοη 5 A

BLe aqueous phase of the incoming to the cathode compartment emulsion consisted of 2 j> acrylonitrile, 2 Ji Adipineäurenitril, 86.0 f of water and 10 j »Lithiumohlorid. Its Pg value was 3. The oil phase of the emulsion "passed" from 48.0} C Aorylnitril, 35.0 i> Adipineäurenitril, $ 5 water and 0.2 Jt Lithiumohlorid you six hours electrolysis was performed. The selectivity was 18.3 1 "for propionitrile, 74.0 jt.ftt * Adipinsäurenitril, 7.5 ji for Aorylnitriloligomeree and 0.1 + for Bisoyanäthyl ether, "lied about the consumed by the electrolysis te aoryl nitrile.

Example · It ^

Sin a surface τοη 10 χ 10 em and a lead-antimony anode was provided with the same surface,

3D was used · The anode compartment and the cathode compartment the cell were through a cation exchange di aphr agma Au · sulfonated em K. vinylbeneol-styrene-butadiene-0opolymerisat separated from 1 mm IÜoke. The cathode compartment and the anode compartment had a length of 10 om and a width of 10 om. The distance between the electrode surface and the surface of the diaphragm was kept at 1 mm by spacers. The anolyte was with a pump between the anode compartment and the Anolyte container and the catholyte with a pump between He keeps the cathode compartment and the catholyte vice versa wallows. In-sulfur acid solution was used as the anolyte

009839/2153

a flow rate of 10 om / sec. circulated.

An emulsion, which consisted of 100 parts of an aqueous phase and 50 parts of an oil phase, was fed to the cathode compartment and at a flow rate of 50 om / sec. circulated and " ^{electrolyzed at 40 0} C with a current of 10 A ·

They aqueous phase of the emulsion fed to the cathode compartment "consisted of 2 i" acrylonitrile, 5 »1 # Adipinsäurenitril, 0.6 i» propionitrile, a very small amount Biscyanäthyläther, 0.15 J * Aorylnitriloligomerem, 71.4 f> water, 17 , 0 ° i tetramethyl ammonium sulfate, 3.5 # triethylamine and Triäthylaminbenzolsulfonat. your _pH value was 8. The Ölphaee consisted of 23 # acrylonitrile, 58.9 # Adipineäurenitril, 7.7 f> propionitrile, 1.7 + Aorylnitriloligomerem, 6 j £ water, 2 i 'tetramethyl ammonium sulfate as, 1 1 "of triethylamine and Triäthylaminbenzolsulfonat. the Adipineäurenitril, propionitrile, the Bisoyanäthyläther and Aorylnitriloligomere were circulated electrolysis products.

During the electrolysis, acrylonitrile was added to the emulsion draining from the cathode compartment. The emulsion obtained was adjusted to the above-mentioned composition and homogenized. The electrolysis was carried out for 300 hours. The selectivity was 11.3 * for propionitrile, 86.0? 6 for Adipinsäurenitril, 2.5 1 · ligomeres for acrylonitrile © and 0.1 i "for Biscyanathylather, based on the power consumed by the electrolysis of acrylonitrile. The emulsion running off from the cathode compartment was drawn off from the catholyte container and used to separate the oil phase

009839/2153

ditched. To separate the lieit salt dissolved in the oil phase, the latter was passed through a continuously operating (countercurrent extraction column) Water was poured into this column drop by drop from above and-the oil phase introduced from below., the amount of The electrical salts contained in the oil phase were extracted using an amount of water which was only 1/10 of the amount of oil phase was decreased to less than 0.03 #

The adiponitrile was obtained by distillation treated oil phase recovered

Example 22

The electrolysis cell described in Example 21 was used. As anolyte, 6.5 N sulfuric acid was fed in and the mixture was flowed in at a flow rate of 30 cm / sec. circulated - ,. '■ -

In d'en cathode compartment was an emulsion consisting of an aqueous phase and an oil phase 50 parts of 100 parts, are introduced and electrolyzed at a flow rate of 30 cm / Sekο circulated and at 4O ⁰ G with a current of 15 A

The aqueous phase introduced into the cathode compartment emulsion consisted of 4.5 i »Aorylnitril, 7.5% Adipinsäurenitril, 77.5 & water 11.0 # Kaliumbenzolsulf onate and 3,5 ⁴ ^ hexamethylenediamine-p-toluolsulfonatο your p ^ value bötrug 3ο oil phase consisted of 33 j> Aorylnitril, 55% Adipinsäurenitril, 3 $> ■ potassium benzenesulfonate, 2 $> hexamethylenediamine-p-toluenesulfonate and 7 S * ^ _Wassere;

00983972153

Pie electrolysis was 10 hours · carried out the energy consumed by the electrolysis acrylonitrile was converted to 9.3 i "in propionitrile to 80.5 * f> in Adipinsäurenitril to 10.1 i" in Aorylnitriloligomeres and 0.1 ^ in Bisoyanäthyläther

Example 23

The electrolyzing cell described in Example 21 was used. A 0.5N solsulfuric acid solution was used as the anolyte circulated at a flow rate of 30 om / sec.

An emulsion consisting of 100 parts of an aqueous phase, and 50 parts of an oil phase was introduced into the cathode compartment and is circulated at a flow rate of 30 cm / Seke and "at 4O ⁰ C with a current of 10 A elektrolysierto

The aqueous phase introduced into the cathode compartment emulsion reads and 4 i> acrylonitrile, 3.5 $> Adipinsäurenitril, 71 $ 5 $> water, 17.0 $> tetraethylammonium chloride and 3.5 i »hexamethylene-p-toluene sulfonate Your The Pjj value was 7. The oil phase "consisted of 45.5 $ acrylonitrile, 40.0 $> adiponitrile, 6 % water, 1.1 $ lithium chloride and 1.1 # hexamethylenediaminesulfonate. The electrolysis was carried out for 6 hours electrolysis consumed acrylonitrile was <$> converted to 3 »Ö fi in propionitrile to 89.0 in Adipinsäurenitrilj to 7.9 ^ ⁱⁿ · Aorylnitriloligomeres and 0.1 in 56 Bisoyanäthyläther ·

009839/215 3

■ · ■ .- 59 =

Example 24

The electrolysis cell described in Example 21 was used. As the anolyte, a 1N sulfuric acid solution was introduced and at a flow rate of 30 om / sec. circulated.

An emulsion consisting of an aqueous phase and an oil phase 30 parts of ", 100 parts, was introduced into the cathode chamber and circulated at a Strömungsgesohwindigkeit 30 om / sec. And at 5Q ⁰ C with a current of 10 A elektrolysierto

The aqueous phase introduced into the cathode compartment emulsion "consisted of 2 i> acrylonitrile, 5,4 & Adipinsäurenitril, 74.7 i · water 17.0 $> Tetraäthylammoniumsulfat and 0.3 6 Sohwefelkohlenetoff She had eineg ^ _H?. - Value of 3. The oil phase "consisted of 22.7 f aoryl nitrile, 63.5 + adipic acid nitrile, IfL. Water, 2.1 i> Tetraäthylammoniussulfat and 0.3% SohwefeUcohlenstoff. Electrolysis was three hours durohgefUhrt · The power consumed by the electrolysis acrylonitrile was about 3.3 i "in propionitrile, su 93.6 i "in Adipinsäurenitril, zn 2.9 f Acrylnitriloligomeres and ewandelt to 0.2 Jt in Bisoyanäthyläther UB ^.

When used as inhibitors of anionic polymerization other connections, e. B. p-Toluenesulfonate, OOS, Oo and acetylene compounds are used instead of carbon disulfide, adiponitrile is used in obtain high yield "

009839/2153

Example 25

The electrolysis cell described in Example 21 was used, but with the cathode made of platinum existed and a 1,5N-Sohululeäurelösung as anolyte with a flow rate of 5 om / sec. was circulated ο

An emulsion, which consisted of 50 parts of an aqueous phase and 150 parts of an oil phase, was introduced into the cathode compartment and circulated at a flow rate of 70 cm / sec and ^{electrolyzed at 30 0} O with a current of 7 A.

The aqueous phase introduced into the cathode compartment emulsion consisted of 2 j6 Aorylnitril, 2 i "Adipinsäurenitril, 80 i» Water, 11 # Lithiumohlorid and 4 $> Hexamethylendiaminbenzolsulfonat. Their p ^ value was 4

The oil phase consisted of 46 i »Aorylnitril, 36 i 'Adipinsäurenitril, 5 i" of water, 0.2 # Lithiumohlorid and 2f> Hexamethylendiaminbenzolsulfonat _e The electrolysis was 20 hours run the selectivity with respect to the electrolysis product was 14 # of propionitrile, 78 i> for Adipinsäurenitril, 8 i "for Acrylnitriloligomeres and 0.1 for 96 Biscyanäthyläther, based on the power consumed by the electrolysis acrylic, nitrilo

Example 26

If all the experiments described above are repeated under the conditions mentioned in Example 1a and 13a become, ie. if a solution as an aqueous phase of the catholyte is used in place of the emulsion, results similar to those in Example 1a are obtained

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and 13a correspond to the results mentioned, d ₀ ho the selectivity for propionitrile increases significantly

'Cost of selectivity for adiponitrile. Further soheidet during operation polymer in the cathode space and at the cathode, so that the operation must be aborted sohließlioh ₀

Polymer also separates on the cathode and in the cathode compartment and sohließlioh clogs the cell when the in the preceding examples. Very even "experiments in the manner described in Examples Ib and 13b, do ho be repeated without the inhibitor of anionic polymerization _o

From the above description it can be seen that the electrolytic dimerization of acrylonitrile according to the invention has numerous advantages over the previously known and proposed processes. One of the main advantages to be mentioned is working with a lower concentration of aqueous dissolved acrylonitrile than was previously possible ο This concentration is completely outside the range used in the known methods «, Working within this range,; which for the first time according to of the invention is "-möglich, has numerous advantages, for ₉ B ₀ the reduction of the formation of the 0Iigomeren, the possibility of using cheaper control or current carrier salts and the ease of P _r oduct deposition and extraction ,, further, it is the method according to According to the invention, it is possible for the first time to achieve an almost quantitative yield of adiponitrile and to maintain operation for a long time without interruption without the selectivity or yield of adiponitrile gradually decreasing

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The problem of polymer formation during electrolysis sohon always passes all attempts made so far, to suppress them, e.g. B. by adding a radical polymerization preventing inhibitor were unsuccessful. The solution achieved by the invention this problem is based on the plague that the polymerisation problem does not result from a free radical polymerisation, but from a results in a completely different polymerization mechanism, which is not the result of the formation of free radicals, but the consequence of the electric field or potential is, and without any commitment to any particular ! Theory is intended to be more anionic Polymerisationsmeohanismus can be designatedο In any case, the addition of the anionic polymerization inhibitor according to the invention switches effectively solves the polymerization problem that has arisen up to now and the problem of polymer segregation and clogging of the cell, which is usually present the cathode and took place in the cathode compartment. Furthermore, the formation of propionitrile is suppressed, the attributable to these deposits and clogging "

In the method according to the invention, the additional Presence of inhibitors of free radical polymerization, z <, B, of hydroquinone and the like, not excluded, but it is clear state that these free radical polymerization inhibitors are completely ineffective in terms of the suppression of the type of polymerization which is a problem in the cathode compartment *

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Here, too, we do not intend to lay down a theory, but it is assumed that when the emulsion is used in contrast to a solution as a catholyte, the combination of the complete aqueous phase and the dispersed oil phase at the cathode effectively results in the formation of a gradient in the aorylnitrilverbrauoli in the area of the cathode surface is prevented and the acrylonitrile is made accessible and available for effective hydrodimerization of the cathode surface. It is assumed that the inhibitor of anionic polymerization does not only effectively prevent polymerization, which occurs in the concentrated oil phase, but from any one Basically it also keeps the cathode surface activated for the hydrodimerization reaction and suppresses the formation of propionitrile. This effect can be increased by using a hat colloid. As already mentioned, the combination of ran lasser with a hat colloid is used as an inhibitor r anionic polymerization effective »while water alone is ineffective for this purpose ·

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Claims (18)

Claims 1) Process for the production of adipic acid nitrile duroh electrolytic hydrodimerization of aoryl nitrile, with electrolytes containing acrylonitrile and conductive salts as current carriers, in particular Catholyte, is worked, characterized in that an oil-water emulsion is used as the catholyte, which the acrylonitrile in the continuous aqueous phase in a concentration below 5 Grewo- ^ dissolved and so sufficient in the oil phase Amount contains that acrylonitrile from the oil phase into the aqueous phase when the water is consumed dissolved aorylnitrile and that the catholyte continues to be an inhibitor against an anionic Polymerization initiation is added in such an amount that one by the electric current triggered polymerization of the acrylonitrile in the emulsion is practically prevented. o 2) Method according to claim 1, characterized in that that one works with conductive salts which have only low oleophilic properties. 3) Method according to claims 1 and 2, characterized in that that the electrolyte salts used are alkali or alkaline earth metal salts, Ammonium salts or quaternary ammonium salts are used, but here quaternary ammonium salts with low oleophilic Properties such as those salts with a total of not more than 10 bound to the nitrogen Carbon atoms, are preferred 4) Method according to claim 3, characterized in that. as. Conductive salts sulfates, halides, phosphates, 009839/2153 ... .--., "- noggpq V.4.8.1V62J New Jr ^ '^ Aryl sulfonate, aralkyl sulfonate, alkyl sulfate and /, or carboxylates of aliphatic, aromatic and / or heterocyclic quaternary ammonium compounds are used. 5) Process according to claims 1 "to .4» characterized in that the emulsion is also an organic Contains solvent, which preferably "has" only low solubility in water 6) Process according to claim 5 »daduroh characterized -JO that at least one electrolysis product, which can also be a by-product of the process, is used as an additional solvent, in particular adipic acid nitrile and / or propionitrile being present in such an amount that the concentrations are ". -. Tration of the aoryl nitrile dissolved in the aqueous phase was less than half" of 5 _{grains 5} - $ 7) Method according to claims 1 Ms 6, characterized in that that as an anion polymerization InhilDitor at least one of the following compounds is used williApaine "or amine salts, ammonia or Ammonia salts ,, alcohols, organic or inorganic Acids, acetylene compounds, mercaptans, dialkyl sulfide, oxygen, carbon monoxide, carbon dioxide, carbon oxysulfide, carbon monosulfide or Sohwe- "felköhlenstöff, in particular at least one of the following compounds is used »hexamethylenediamine, I) imethylhexamethylenediamine, Cyanoethylhexamethyrendiamih or salts of these compounds. -. ⁸ ) Method ^ naoh claim: "f, characterized in that the anion polymerization inhibitor is 009839/2153 Mouths with active hydrogen atoms are used, 9) Method according to Anspruoh 1, characterized in that the water-containing catholyte Sohutzkolloids, such as alkyl-substituted and / or carboxylated oiluloses, Tragacanth or protein materials are added, in particular also as anion polymerization inhibitors works. 10) Process according to claims 1 ", characterized to 9, wherein" is carried out at _pH values in the range of 1 ms 10, preferably between 3 and 6, " 11) Process according to claims 1 "to 10, characterized in that" at temperatures from 0 "to 80 ⁰ C, preferably from 15" to 70 ⁰ C, is carried out » 12) Method according to claims 1 Ms 11, characterized in that that catholytes are used, which are the conductive salt in the aqueous phase of the emulsion in an amount of about 1 Ms 60 wt »- 6 and den Anion polymerization inhibitor in amounts of approx. 10 ppm Ms 20 G-ew "- # contain" 13) Method according to claims 1 Ms 12, characterized in that that one works with a cell divided by a diaphragm and that the catholyte does so is passed through the cathode compartment so that the emulsion is always brought into intimate contact with the cathode will. 14) Method according to claims 1 Ms 13, characterized in that an aqueous mineral acid solution as the anolyte, especially an aqueous sulfuric acid 009839/2153 solution, is used. 15) Method according to claims 1 Ms H, characterized in that that a Kationenauetausohmembran as a diaphragm is used· 16) method naoh claims 1 Ms 15, characterized in that that with cathodes made of copper, cadmium, tin, HLei, mercury and / or their alloys is being worked 17) Method naoh claims 1 "to 16, characterized in that emulsions are used as catholytes in which the weight ratio of oil phase to aqueous phase is between 5 t 1 and 1 t 100, preferably the content of dissolved acrylonitrile in the aqueous Phase between about 2 and 5 Sew _e -Si lies ₉ while in the oil phase he can make amounts between atwa 1. xmä 99 Gew _e - ^ 18) Process according to Claims 1 to 17, characterized in that current densities between about 3 and 30 A / äM are used. 00 983 9/2153 BAD ORiG! MAL